Hydraulic drive for stoker rams



July 3, 1923. 1,460,586

C. L. HOWSE HYDRAULIC DRIVE FOR STOKER RAMS Filed March 2. 1922 4Sheets-Sheet l July 3, 1923. 1,460,586

c. L. HOWSE HYDRAULIC DRIVE FOR STOKER RAMS Filed arch 2, 19224.Sheets-Shqet 2 I Q 'N- \1 n I Q Q l i I r u unn... E w I I h J iJEIL'I July 3, 1923.

1,460,586 c. 1.. HOWSE HYDRAULIC DRIVE FOR STOKER RAMS Filed March 2,1.922 4 Sheets-Sheet 5 July 3, 1923. I

c. HOWSE HYDRAULIC DRIVE FOR STOKER RAMS Filed March 2, 1 922 4Sheets-Sheet 4 fi/MP/ 2165/" (Cewf/s 4/). fir 0 51/5 (-1- Patented Ja13', 1e23.

UNETED STATES oure'rnsn HowsE, or DETROIT, MICHIGAN, Assrenon T0'rnnunnnnrnnn s'roxna v intense earsn'r orriea.

COMPANY OF AMERICA, A CORPORATION OF NEW JERSEY.

HYDRAULIC DRIVE ron STOKER RAMS.

Application filed March 2, 1922. serialNo. 540,647.

To all whom it may concern: I

Be it known-that I, CURrEs L. Howsn,

a citizen of Great Britain, residing at Detroit, in the county of Wayneand State of Michigan, have invented certain new and useful Improvementsin Hydraulic Drives.

for Stoker Rams, of which the following is a specification.

.My invention relates to a hydraulic system of stoker-ram actuation, andhas for its general object to ,provide novel, eflicient, economical andflexible equipment by means of which the rams may be automaticallyoperated. For attainment of these and other objects which will becomeapparent herein after, I provide advantageous means for supplyingpressure impulses at regular intervals, preferably automaticallyvariable as t time, in a piping system with which the ram-engines andcontrolling mechanisms are connected, and provide advantageouscontrolling means whereby each ram engine is actuated periodically, inaccordancewith selectively predetermined numbers of impulses.

, drawings wherein I .have illustrated embodiments ofmy invention indiagrammatic form, for clarity, without attempt at} delineation of exactproportions ordetails, which may vary with different installations; Fig.1 is a perspective diagram showing a complete driving system for aplurality of stoker rams; Figs. 2and 3 are front elevations with partsbroken away showing an impulse-actuated valve in different positions ofoperation; Fig. 4: is a side elevation of the valve mechanism; Fig.

4 5 is a section through an impulse-controller showing another modifiedtaken on line 5-5 f Fig. 6; Fig. 6 is a section therethrough taken online 6-6" of Fig. 5; Fig. 7 is a diagrammatic view showing a modifiedembodiment of my invention; Fig. 8 is another diagrammatic view Ininvention. I

' eferring to Fig.1, the'furna'ce 10 may be equipped with any suitablecharacter of underfeed stoker, fuel being fed to the retorts (not'shown)from the lToppers 11 by means of ram mechanisms .12 each of which isreciprocable by a hydraulic engine 1300mprising a piston 14 connectedwith the ram and a cylinder 15 closed at both-ends. Air

' to support combustion may be supplied from a suitable fan 16 thatpreferably-is driven at a speed variable in accordance with"theembodiment of demand requisite for maintaining a given steam pressure inthe boiler, one available form of construction, as shown, providing avariable speed fan-engine 17 the steam-line 18 of which is governed by,a suitable pressure regulator 19 and is connected to the steam header 20for a suitable boiler 21. As steam pressure dropsin the boiler, enginespeed and consequently fan speed are augmented, and vice versa.

:[t is usually desirabIe t hat the rate of- .fuel supply to all of theretorts shall likewise be varied, to increase the fuel supply when theboiler-pressure drops and to decrease it as such pressure rises, and asone means for this accomplishment I illustratea controlling art of thehydraulic system as speed-contro led from the fan shaft.

In the hydraulic syst'em, the pump 22 of suitable construction may bedriven in any v desired fashion asby an electric motor 23, operating todraw liquid, such as oil, from a supply source or chamber 24: anddeliver it to the main pressure pipe 25 for utilization in operating theram-engine, the liquid so pumped ultimately returning .to the supplysource through a return-pipe 26. In order that, if desired, a maximumpressure may be established under which .the hydraulic system willwork,an unloading valve 27 may be provided connected by pipe '28. be-

with boiler pressure, drives an automatic reversing valve 33 by suitablepower connections 34: such as belt' and pulley,v such re-- versing valveoperating periodically to connect two engine pipes '36 and 37withrespectively the pipes 25 and 26', and then to reverse this connection.-Theevalve may be constructed in various ways, Figs. 5 and 6 showing asimple construction in which the cylinder '39 contains a double-headedpiston 40 mechanicallyreciprocated by an ecc'entricAt-l carried by shaft42 which is driven by the stated power connections 34.

Pipe 25 has two branches 25 and 25 opening respectively to opposite endsof the cyllie inder; pipe 26 leads to the middle of the cylinder, andpipes 36 and 37 open to the cylindermidway between the three portsmentioned, so that as the piston is thrown to either side of the deadcenter position illustrated, it opens one of the pipes 36 or 37 to thehigh pressure connection 25 and the other thereof to the return pipe 26.

Pipe 36 has open branch connections 36 to one end of each cylinder 15,preferably the outer or head end, so that the pistons stand normally atthe ram-end of their cylinders, and branch pipes 37' of pipe 37 areconnectible at intervals with the ram-ends or inner ends of thecylinders. In Figs. 2 to 4 is shown a form of impulse valve suitablenormally to close a pressure pipe 37 but actuatable to open it to theengine cylinder after a selectively determinable number of impulses. Avertical cylinder 38 has opening to it at difi'erent levels the pressurepipe 37" and the piping connection 37 which communicates with the ramend of the cylinder. CORP munication between pipes 37 and 37 is normallyprevented by a piston 39 having a piston rod 40 which extends throughthe end wall of the valve casing for cooperation with a ratchet-movablestop mechanism 42. At each throw of the piston 39 in response to apressure impulse communicated through pipe 37', the piston rises againstthe tension of spring 40 from position shown in Fig. 2 to position shownin Fig. 3, enough to operate the ratchet mechanism, but not enough toopen the passage between the valved pipes. The ratchet mechanism,

.thus advanced, carries along with it the stop for the valve stem 40.,so that after a predetermined number of these impulses have been thustransmitted to the ratchet mechanism, the stop is completely removed,from the path of the valve stem, and on the next succeeding pressureimpulse the valve is free to-rise to the dotted-line position shown inFig. 3, opening communication between the two valved pipes.

In the specific mechanism shown the piston rod is provided with asecond, balancing piston 39 below the level of the pipe 37; a duct 43leads through the valve cas-' ing wall from the chamber between saidpistons to'the otherwise-closed bottom chamber 44 in which is arranged aspring 45 which stands fully expanded when the parts are in the positionshown in Fig. 3. A needle-restriction 46 may be' employed toadjust thecapacity of such duct. Thus the valve is practically balanced, exceptfor the pressure communication to the bottom of piston 39 effectedthrough the duct 43. and the valve may thus be prevented from re ceivingtoo spasmodic an actuation; its rapidity of response to pressureapplication being variable by adjustment of the restriction 46.

until caught by such pin 52. A stop sector 3 55 is pivoted on shaft 54,and, when in position shown inFig. 1, is interposed in the path ofmovement of valve-stem 40 to limit the upward movement of said stem.This sector may be carried clockwise by the ratchet sector 50, as by apin 56 in the ratchet, but gravity tends to return it always to theposition shown in Fig. 1. When the ratchet reaches the position shown inFig. 3 the stop sector 55 is removed from the path of vertical motion ofthe valve stem 40. \Vith the ratchet sector there cooperates an activeor moving pawl 57 and a holding pawl 58 which cooperate'with each otherand with the valve stem 40 in such fashion that as the valve stem risesto the brief extent permitted before it encounters stop 55,

'the live paw-l 57 is caused to advance the ratchet one step, but' whenthe valve stem, freedirom the restraint of the stop 55, makes a fullexcursion, both the live pawl and the holding pawl are thrown out ofengagement with the ratchet so that it, and

thestop sector, may both be gravity returned to initial position. In thespecific construction shown pawl-carrier 60 is pivoted on shaft 54 andnormally hangs in such position that its cam face 61 is interposed inthe path of upward movement of a pin 62 on the valve stem. The live pawl57 is pivoted at 63 to the carrier and has a tail 64 which projectsbeyond the cam face 61 of its carrier but above the level to which pin62 may rise if the valve stem be stopped by the stop sector 55. The pawl57 works so close to holding pawl 58 that if the former be thrownmaterially away from the ratchet, it will" carry the holding pawl out ofengagement with the ratchet also. 7 i

The operation of the system above described will now be apparent: Thepump 22 and pressure tank 30 maintain substantially constant pressurein-the pipes 25 and 25 of the reversing valv which. operating with afrequency determined by the demands of the boiler pressure by virtue ofits actuation from the pressure-governed engine, serves to supplypressure impulses alternately through the pipes 36 and 37, that pipewhich is not so receiving pressure being connected through thereversing. valve with a return pipe 26 leading to the source of liquidsupply. lmpulses communicated through pipe 36 ordinarily do nothing, asthe pistons 14 stand normally at the ram-ends of their cyl-' inders. Buteach impulse transmitted through pipe 37 to one of the ram-engine sectorone step. The number of steps necessary to be taken before the valve canfulliy open is determined by the preliminary a justment of the pin 52.Finally, however,

the'rise of the valve stem is freed from restraint of the holding sectorand the valve stem may pass by the position shown'in fulllines in Fig. 3to that shown in dotted lines in Fig. 3, rising on its full stroke toopen the stated communication between pipes 37 and 37 and to enablepin62 to strike the tail 64 of pawl 57, throwing 'both*it and theholding-pawl out of engagement with the ratchet. both the ratchet sectorand the stop sector tend to return by gravity to their initialposition,- 'the ratchet sector efiecting an immediate return, and thestop sector returning as soon.as the valve ste n 40 drops out of itsway. Under these conditions a pressure impulse of suitable duration iscom,- municated to the ram end of the cylinder to retract the ram, theliquid normally is in the outer end of the cylinder 15, finding .esca

throughbranch pipe36', pipeg36 and t e reversing valve 33 to the returnpipe 26. Upon the occurrence of the next pressure impulse through pipe36' the ram is driven on its in-stroke, the liquid which was in theram-end of the cylinder being forced out through pipes 37 and acting,against the tension 0 light spring 45 and dash-pot effect of therestricted duct 43, to force the valve 39 downward, openingcommunication to pipe 37' and thence through pipe 37 and the reversingvalve 33 to the return pipe 26.

It will be observed that the requisite mechanlsms are very simple,rugged, and inexpensive, and that with minimum piping requirement theinstallation may be made with the greatest flexibility as to theplacenient of the respective parts of the apparatus.-

In Fig. 7 -I have diagrammatically 'illus-- trated a system employing apump 22, illustrated as a rotary pump, supplying liquid from reservoir24 to pressure tank 30, the

pressure supply .pipe 25 and return pipe 26' being alternativelyconnectable by a rotary reversing valve 33"with a single pipe 37 all ofthe valves 42 as heretofore descri for the several engines, each suchvalve being arranged to control the pressure While this conditionendures,

impulses to the head end-of the engine l3,

Piston return pressure is supplied through pipe 36 from an accumulator70, the constant pressureof the accumulator being less I than thepressure supplied from the chain- 30. i I f In Fi 8 .a constructiongenerally similar to that own in Fig. 1 is illustrated in simplifiedform save that a rotary pump 22 and a rotary valve 33' are indicated inlieu of the understoo by those skilled in the art that in the broaderaspects of my invention it is 4 not restricted to details ofconstruction and arrangement illustratively' pointed out, but

that many changes in construction and arrangem'ent may be-i'nade withoutdeparture from the spirit of my invention within the scope of theappended claims.

I claim: r I

1. In a stoker-ram drive, the combination with a ram, of an enginetherefor, pressureimpulse sup-pl means for onejend of said movements ofsaid valve operatable by the movement of said valve within its closedrange, .to remove the valverestraint after a predetermined number ofimpulses.

2. In a Stoker-ram drive, the combiiim.

tion with a ram, of an engine therefor, means cylinder inclu ing areciprocable, normally for supplying pressure impulses, connections Itherefrom to one end of theengine cylinder includin to limit t evalve'movement within its closed range, and a step-by-step mechanismoperatable by such limited movements of the valve for moving saidrestraining means to free the valve. V

3. In a Stoker-ram drive, the combination with aram, of anenginetherefor, means for suppl ing pressure impulses, 'connections thei i'om to one end of the engine cylinder an impulse movable valve,means in uding a valve normally closing said con-v nections andpressure-movable to open the same, stop means for preventing opening ofthe valve, and means operated by the valve for periodically disablingsaid stop means.

4. The combination. of a filffirality of Stoker-ram engines, means forsupplying hydraulic pressure impulses, connections from said means toeach ofsaid engine's including for each engine a pressure-movable valveclosing said connections when the valve is :moved to a limited range andopening said connection when said valve is moved through a larger range,a stop mechanism for each valve normally limiting its movement totheclosed range, and means operable by the valve for moving such stoptoinoperative position.

closing said connections when the valve is moved to a limited range andopening said connection when said valve is moved through a larger range,a stop mechanism for each valve normally limiting its movement to theclosedrange, and means operable by the valve for moving such stop toinoperative position, said means being selectively settable topredetermine the number of impulses requisite to free the valve foropening operations.

6. The combination with a ram-engine and a pressure-impulse transmittingmeans, of a valve connected between said transmitter and engine, and,when unrestrained, pressure-movable to open the connections, movablemeans normally restraining said valve against opening, and automatic,selfrestoring step-by-step mechanism for moving said movable means toinactive position.

7. The combination with a stoker-ram engine, and impulse-transmittingmeans, connections between them including a pressure-moved valve adaptedto open said con nections upon full movement of the valving elementthereof, and means actuated by said valve for periodically preventingthe opening movement of said valve on the one-hand and permitting thefull opening movement of the valve on the other hand.

8. The combination of a ram-engine, means for supplying pressureimpulses thereto, a pressure-responsive valve adapt ed to opensaidconnections under pressure from said transmitting means or from theengine, and automatic means for periodically freeing said valve to openunder pressure from said impulse-transmitting means but normallyrestraining said valve against such opening.

9. The combination with a ram-engine having a piston and cylinder, meansfor supplying pressure impulses to one end of said cylinder including acontrolling valve, said controlling valve being pressure operatable toopen said connectionsunder pressure toward the engine or from theengine,

10. The combination of a stoker ram engine, a valve therefor adapted toopen un-- ment, said stop being movable to inoperaanism and a stop forlimiting the valve movetive position by said step-by-step meohanism.

11. The combination with a stoker ram engine, means for supplyingpressure vimpulses, and connections therebetween including a valve, saidvalve comprising a cylinder having non-aligning ports and a valve properslidable therebetween and provided with a valve stem; ratchet and pawlmechanisms operated by said valve stem, and stop-mechanisms for saidvalve stem movable to free the valve for opening movement afterpredetermined actuation of the ratchet mechanism.

12. The combination with a ram-engine of means for supplying pressureimpulses, connections therebetween including a valve, said valve havinga cylinder with non-aligning ports, a balanced-piston valve in saidcylinder with its piston spanning the port connected to the source ofpressure-impulses, and said pistonhaving a ram extending out ofsaidcylinder; a ratchet and pawl mechanism operatable from said pistonrod and a stop mechanism, operatable by said ratchet and pawl mechanismfor normally limiting the movement of said valve and periodicallyfreeing said valve for opening movement.

13. The combination With a boiler furnace, a plurality of stoker ramstherefor, and respective engines for said rams, of a hydraulic pump,means for connecting said pump with said engine including in a commonportion of said connection a pressureinterrupting valve, means governedby the boiler pressure controlling the periodicity of operation of saidvalve, and, for each engine, an impulse-responsive valve in saidconnection pressure-ope'ratable to open such connection, each such valveprovided with means actuated by the valve and controlling theperiodicity of its opening movement.

engine-pipes connectable with opposite ends of the several engines, areversing valve for connecting one said engine pipe with the pressurepipe and the other said engine pipe with the return pipe and thenreversing said connection; means controlled by boiler pres sure forgoverning the frequency of operation of said reversing valve, and, foreach engine a valve controlling the operation of one of said enginepipes therewith, and settable means, actuated by such valve, forindividually determining the periodicity of opening of said valve.

. CURTES L. HOWSE:

